Get to Know the Traditional Chinese Medicine Known as Xiao Yao San

Xiao Yao San (XYS) is a traditional Chinese medicine formula that has a long history of use for treating depression and anxiety, lowering stress, and managing menopausal symptoms. XYS, made up of eight different herbs, is commonly referred to as “Free and Easy Wanderer” or “Rambling Powder.” There are variations of the formula called Dan Zhi XYS and Jia Wei XYS.

A 2012 systematic review of 26 randomized clinical trials of depression patients who used XYS or its modified variations found that subjects who used XYS in combination with antidepressants experienced better outcomes than those who used antidepressants alone. Those who used the combined therapy reported improved scores on self-rated depression scales with no increase in adverse events.

A subsequent meta-analysis of XYS trials that included more than 3,500 patients concluded Chinese herbal medicine led to better clinical outcomes based on scores on the depression scales and caused fewer adverse events compared to antidepressants. Another review of patients with cancer reached a similar conclusion: The cancer patients who used XYS experienced fewer adverse events and side effects than those who used conventional antidepressants.

Jia Wei XYS was studied in a small eight-week randomized trial that included 191 patients with depression and anxiety and compared Jia Wei XYS to the drug sertraline. The researchers found the Chinese herbal formula performed comparably to the conventional drug, with sustained benefits noted four weeks after the trial period concluded. The subjects who used Jia Wei XYS in the trial reported lower adverse events, improved anxiety, and better sleep.

Most of the studies conducted on XYS have been limited by small sample sizes, risk of bias, and variations in duration and dosage, so scientists say more research is needed. Two of the formula components, Dang Gui and Licorice, are known to have estrogenic properties, but it is unknown whether these ingredients act as phytoestrogens. Use of this Chinese herbal formula may cause side effects such as headaches, dizziness, fatigue, and diarrhea. In addition, XYS may interact with other drugs, so patients should discuss with a physician prior to use.